1. Field of the Invention
This invention relates to a device and method for removing oil from an oil filter. In particular, the invention relates to the use of high pressure air to blow oil out of an oil filter of the kind used in a motor vehicle so that the filter may be disposed of in an environmentally safe manner.
2. Description of the Related Art
Proper maintenance of a motor vehicle requires periodic, regular oil changes and replacement of the oil filter. A used oil filter naturally has no further use on the motor vehicle, and so it must be disposed of in some manner. One standard method of disposal of an oil filter is to simply throw it in the trash can and let the garbage hauler dump it in a landfill. Increasing concern over the environment, however, has drawn attention to the disposal of used motor oil, including the disposal of oil filters.
Most landfills do not accept liquids for disposal, especially used motor oil. While the oil filter itself is not a liquid, the oil within it certainly is a liquid. Efforts are being directed at recovering engine waste oil after it has been used and removed from the engine or crankcase of a motor vehicle for proper disposal or recycling. Some states are even mandating by statute the recovery of engine waste oil and restricting disposal of products containing engine waste oil, as for example in Wisconsin by Wis. Stat. Section 144.48, with even more stringent laws recently considered by the Wisconsin Legislature in Senate Bill SB-300.
During an oil change at a service station, only some of the oil can be removed from an oil filter by tipping the filter over and pouring the oil out. Pouring oil out is very ineffective since a significant amount of oil will initially remain in the filter, but then drip out over time. At some service stations which do a significant amount of business in oil changes and throw a large number of used oil filters into a trash bin, a rather large amount of oil has been seen dripping down to the bottom of the bin and pouring out when the bin is dumped into a garbage truck. These filters will continue to drip oil even after disposal at a landfill thus contributing to the difficult problems of contamination at such sites.
Filters of all kinds are obviously used in many applications, and some methods are available to clean some types of filters, but the applicant is aware of virtually no prior art relative to the use of high pressure air for removing oil from an oil filter. For example, U.S. Pat. No. 2,862,622 relates to a filter for a dry cleaning machine in which solid matter is filtered from a cleaning solvent, such as perchloroethylene. This device has a filter body which consists of two vertical cylinder sections 1 and 2 separated by a diaphragm plate 5 having multiple apertures for tubes of fine wire mesh 9. During normal operation the solvent passes from the bottom of the tank upward through the filter tubes 9 where the fine wire mesh filters out particles in the solvent. The filter tubes 9 are cleaned by shutting off the flow of solvent through the tank, and gravity draining the remaining solvent in the tank. The draining has the effect of reversing the flow of fluid through the filter tubes 9, which removes dust and lint collected on the tubes.
U.S. Pat. No. 3,087,622 relates to an oil filter having a means for cleaning the filter. This patent shows a series of levers and valves 45, 50, 55, 60 and 65 which operate so as to shut off the flow of engine oil, and alternately flow a cleaning liquid through the filter. The patent does not show how to effectively remove oil from a standard oil filter used in modern motor vehicles so it may be disposed of in an environmentally safe manner.
U.S. Pat. No. 4,214,882 relates to a portable industrial air cleaner 10 for removing dust from dust-laden air. It shows reverse pulse air valves 152 and 154 disposed within the housing 12 to direct a pulse of cleaning air into the filter passageways 94 and 96 to dislodge dust collected by the filters 86 and 88.
U.S. Pat. No. 4,265,771 relates to an alluvial filter having candle-like filtering elements 14 for filtering ash components from highly viscous liquids such as pitch, liquefied coal, tar and the like. The filter operates at working temperatures of approximately 350.degree. C. The device uses pressurized gas to dislodge debris from the filter candles 14.
U.S. Pat. No. 4,834,883 concerns an apparatus for cleaning a swimming pool filter 10 which has a number of porous filter tubes 13 extending down a large tank 11. The cleaning apparatus 25 consists of a spray nozzle 30 on the end of a wand 26 which is inserted through a drain valve 15 at the bottom of the tank 11, and moved back and forth to spray water up against the bottom of the filter tubes 13. The spray water dislodges contaminants on the filter tubes 13, which drop to the bottom of the tank 11 and flow through the drain valve 15 around the wand 26.
None of the above described devices are useful to remove oil from an oil filter of the kind used in motor vehicles.
The applicant has tried one other effort to remove oil from an oil filter and that was to crush the oil filter with a trash compactor in an attempt to literally squeeze the oil out of the filter. That effort failed, since an oil filter has a strong, rigid body which requires a huge force to crush it. Even a large industrial-size compactor was unable to adequately crush an oil filter to the point where a significant amount of fluid would squeeze out.